Currently, with the development and popularity of the Internet, a distributed system is applied more widely. A distributed file system (DFS) refers to a software system established on a network. The distributed file system is characterized by high cohesion and transparency. The cohesion means that each distributed database node in the system has a high degree of autonomy; and the transparency means that each distributed database node is transparent to an application of a user. However, a speed of response to sharing access between distributed systems affects overall performance of the distributed systems.
In the prior art, in order to solve a problem of information sharing between distributed systems, a switched network-based information sharing manner shown in FIG. 1 is generally used. In FIG. 1, a Central Processing Unit (CPU) in a control system A that serves as an acquirer wants to acquire data in a memory unit in a control system B that serves as a provider, and a process is as follows. (1) The CPU in the control system A sends a request message to a CPU in the control system B; (2) the CPU in the control system B reads data from the memory unit in the control system B according to the request message; (3) the CPU in the control system B returns an execution result carrying the data to the CPU in the control system A; (4) the CPU in the control system A extracts the data from the execution result and forwards the data to an upper system for processing. In the foregoing process, all transmission of the data needs to undergo processing with participation of the CPUs in the control system A and the control system B.
By using an existing switched network-based information sharing manner as an example, in a process shown in FIG. 2, a CPU in a control system A wants to acquire data in a memory unit in a control system B, which means that the control system A serves as an acquirer and the control system B serves as a provider. A specific process is, in a procedure shown in FIG. 2 by using solid lines, when executing a program, the CPU in the control system A needs to acquire data in a memory of the control system B, and the CPU in the control system A sends a request message to a CPU in the control system B through a switch fabric; after parsing the request message, the CPU in the control system B learns that the CPU in the control system A needs to acquire the data in the memory of the control system B, then the CPU in the control system B accesses the memory unit in the memory of the control system B according to the request message and acquires the data from the memory unit; after acquiring the data from the memory unit, the CPU in the control system B feeds back the acquired data to the CPU in the control system A, which is a procedure shown in FIG. 2 by using dashed lines. The CPU in the control system B returns an execution result carrying the data to the CPU in the control system A by using the switch fabric. The CPU in the control system A acquires the data from the execution result and submits the data to an upper system for processing. Therefore, in the switched network-based information sharing manner in the prior art, when the control system A acquires data in the control system, both of the CPUs in the control system A and control system B need to participate in processing. Especially when multiple control systems mutually acquire data in another control system, CPUs in the multiple control systems all participate in processing, so that performance of a CPU in a control system that serves as a provider is excessively consumed in an entire information sharing process, which causes a waste of the CPU. In addition, when a running CPU is faulty in any control system that serves as a provider is faulty, data owned by the control system cannot be accessed by another control system, thereby lowering reliability of an entire system.
Therefore, the prior art has the following disadvantages. (1) The CPUs in the control system A and the control system B both need to participate in sharing control of information, so that the performance of the CPU in the control system that serves as the provider is excessively consumed in the entire information sharing process, which causes a waste of the CPU; (2) when the running CPU is faulty in the control system B that serves as the provider is faulty, data owned by the control system B cannot be accessed by another terminal, thereby lowering reliability of the entire system.